Check valve



Dec. 17, 1968 F. W. DOWDICAN CHECK VALVE 2 Sheets-Sheet 1 Filed 001;. 31. 1966 Jill I! 1 G 1 INVENTOR.

FRANKLIN w. DOWD/CAN Dec. 17, 1968 F. w. DOWDlCAN 3,416,454

CHECK VALVE Filed Oct. 31. 1966 2 Sheets-Sheet F.

INVENTOR.

FRANKLIN W. DOWD/CAN United States Patent ABSTRACT OF THE DISCLOSURE A pump adapted for liquid-submerged operation has a check valve element positioned within its casing to alternately engage the impeller and the seat surface about the inlet to the casing.

The present invention relates to valves, more specifically, to a check valve in a pumping system which utilizes the housing of the pump itself as a housing for the valve element as well.

The submerged sump pump is a well-developed apparatus. There are presently several manufactureres supplying the market. The competition is keen, and slight advantages make big differences in the commercial pattern involving these pumps.

Essentially, the pump comprises .a liquid-tight housing for a motor driving an impeller to flow liquid from a low-point of collection to a higher point of disposal. A sensing element, responsive to the height of the collection in the sump, starts and stops the pump motor.

When the sump pump is stopped, the liquid in the discharge oonduit is left standing from the higher point of disposal down to the newly lowered level in the sump. This is a common condition in sump pump operation.

Without a check valve in the conduit system of the pump, the standing liquid returns to the sump. Subsequent pumping will have to again lift the liquid that was standing to the point of disposal. Therefore, a check valve is customarily provided in the discharge conduit.

A check valve in the discharge conduit of a sump pump may function satisfactorily. However, it is a separate piece of equipment in the assembly. Incorporation of this valve into the housing of the pump would greatly simplify manufacture and be .a tremendous advantage in the highly competitive sump pump market. Further, the location of the check valve in the discharge conduit gives the possibility of air locking the pump which could prevent the pump from building sufficient pressure to openthe check valve.

A principal object of the invention is the incorporation of a check valve element into the housing of a pump.

Another object is to provide a check valve element which will offer substantially no resistance to flow where liquid is pumped through it but aids in even distribution of liquid to the impeller blades.

Another object is to provide a check valve element which will seat with consistent accuracy and with a dynamic and positive action in its basic function of checking back flow.

The invention contemplates .a pump impeller with blades arranged about a central cavity communicated with the inlet liquid and a valve element traveling freely in the central cavity between two alternate positions.

The invention further contemplates the valve element moving into upper engagement with th impeller in the central cavity formed by the blades, in which position the valve element will offer no resistance to the flow of pumped liquid through the rotor, will rotate with the rotor, and will direct the flow of the incoming liquid evenly to the blades.

The invention further contemplates the impeller blades guiding the element as it travels between its two positions and the element spinning as it is guided to its seated position to seat with consistent accuracy and with a dynamic and positive action.

Other objects, advantages and features of this invention will become apparent to one skilled in the art upon consideration of the written specification, appended claims, .and attached drawings, wherein;

FIG. 1 is a partially sectioned isometric view of a pump in which the present invention is embodied; and

FIG. 2 is an exploded isometric view of the pump impeller, valve element and bottom plate of the PUIITIP.

General pump arrangement and operation Referring to FIG. 1, a complete sump pump is disclosed. The pump comprises a casing 10 which must be fluid-tight to protect the motor which is in the upper portion 11 of the casing. Power connections, not shown, are provided to the pump through appropriate fluid-tight connections into the housing. I

An on-ofl switch between the power source and motor is not disclosed. This switch is pressure responsive to the hydraulic head of the liquid collection in the pump. Pipe 12 is not completely shown, to avoid conflict with the inventive disclosure. Pipe 12 communicates the pressure of liquid collection head to the on-oif switch.

The impeller 13 is at the bottom of the casing 10, mounted for rotation, by the motor, on shaft 14. The impeller and shaft are locked together through key 15. Rotated by the motor, impeller 13 forces liquid of the sump up discharge pipe 16.

The casing 10 includes a bottom plate 17'. Legs 18 are moulded on the plate 17 and are the members of the casing 10 which actually rest on the bottom of whatever sump in which the pump is placed. Through these legs, the liquid is drawn under plate 17 to enter central inlet 19'.

The blades of the impeller then move the liquid to outlet 20, connected to standpipe 16. Valve element 21 is moved up and away from the inlet 19 to allow the liquid to move into casing 10 with no restriction added to that offered by the size of the inlet, outlet, impeller blades, etc. When the motor is stopped, valve element 21 moves onto its seat as will be discussed infra. The liquid in standpipe 16 is held in pipe 16, up to the point of disposal. The pump, therefore, remains fully primed for its next on period.

The valve element relation to the impeller blades FIGS. 1 and 2 should be considered together to understand how the valve element 21 cooperates with the structure surrounding it. Impeller 13 comprises a plate portion 22 with a central hub portion 23 which has the axial hole into which shaft 14 is journaled. The working elements of this impeller are the blades 24 which depend from the lower surface of plate portion 22. It is this blade structure which actually contacts the liquid pumped and moves it from inlet 19 to outlet 20.

These blades 24 may take various forms. However, a common denominator of blade structure and arrangement, for the purposes of this invention, is the provision of the equivalent of edges 25 which extend vertically from the lower surface of plate portion 22 down to close to the upper surface of bottom housing plate 17. These edges 25 then function as a guide for valve element 21. The valve element 21 nests within the cage, or cavity, formed by edges 25, the upper plate portion 22 and bottom housing plate 17 The valve element relation to the hub section of the impeller The portion of the impeller 13 adjacent the central hub 23 and inside the plate portion 22 is shaped, on its under side, to receive the upper rim 26. Specifically, a channel 27 is formed to loosely receive the rim 26 of valve element 21 .and thereby engage the valve element, as a complete body, in a positive manner.

This portion of the impeller sets the upper limits for the movement of the valve element in its cage, or cavity. Additionally, it engages the element for a functional purpose to be disclosed infra. FIG. 1 discloses the valve element in its upper position, against the impeller plate 13, rim 26 fitting within channel 27.

The valve element relation to the bottom casing plate 17 Valve element 21 is not disclosed in position on the upper surface of bottom plate 17. It should be apparent that, in its lower position, valve element 21 engages the surface 28 of plate 17 about inlet 19 with rim 29.

The engagement of seat surface 28 with rim 29 is in the sealing sense. With pressure applied to element 21 from above, a seal against leakage of liquid through outlet 19 results. The mechanical relation of valve element 21 to the structure forming the cage of the element should be apparent from the drawing and the foregoing description.

The valve element relation to the liquid pumped Valve element 21 with the casing functions as a check valve with respect to the liquid. The liquid is flowed into the impeller casing by the impeller rotation. The element 21 is readily forced to its upward position by the liquid where it offers no significant restriction to the liquid flow between the inlet 19 and outlet 20.

Additionally, the valve element 21 guides the flow of liquid up through inlet 19 into contact with blades 24. The central portion of element 21 is formed downward into a cone 30. The upwardly flowing liquid stream is radially directed by this cone, distributing evenly to the blades 24 rotating about it. Therefore, the valve element 21 has a function in addition to preventing back-flow of the liquids through inlet 19.

During rotation of impeller 13, element 21 is pressed upward, by the liquid flow, into positive engagement within channel 27. The element rotates with the impeller, through the friction of this contact. When the impeller is stopped, the element continues to spin, maintaining its centralization by gyroscopic action.

Holes 31 are formed vertically, through impeller 13 to communicate the liquid on the upper side of the impeller with interior of the valve element 21 within the circle of the rim 26. In this manner, development of a pressure differential is obviated between the interior of element 21 and the underside of impeller 13 to hold element 21 against the impeller when it is not rotating. The valve element descends as liquid flows back into the housing and seats on surface 28 about inlet 19, preventing liquid from flowing from outlet 20 through inlet 19. The spinning of element 21, during its descent, tends to centralize the element over inlet 19 and to engage rim 29 with seat surface 28 in a wiping action which results in an effective, dynai ically formed, seal against liquid flow over the seat surface 28.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense,

The invention having been described, what is claimed is:

1. In a pump comprising a housing, an impeller and a motor to drive the impeller, a check valve, including,

an inlet connection in the housing,

a seat area within the housing about the inlet connection,

an impeller within the housing, arranged to rotate the blade elements about the seat area, leaving a central cavity about the center of blade rotation,

an outlet connection in the housing, including a standpipe up which pumped liquid is forced to an elevated point of disposal,

and a valve element nesting as a free floating body Within the central cavity of the impeller blades, arranged to be guided by structure arranged and associated with the cavity and to be moved by liquid pumped into the housing to engage the rotating impeller structure when the impeller is rotated and to be moved by liquid returning into the housing to seal to the seat area when the impeller is stopped.

2. The valve of claim 1 in which,

the valve element and impeller blades are arranged and sized for the valve element to be guided in its travel between its alternate positions by the inner edges of the blades.

3. The valve of claim 1 in which,

the valve element is provided with a conical surface about its axis of travel which will give it the tendency to maintain its alignment with the seat area as it is moved by returning liquid when the impeller is stopped and will aid in evenly distributing the incomr ing liquid to the blades when the impeller is rotated.

4. A pump mechanism comprising a motor and impeller driven by the motor, the impeller rotating in a plane, including,

a housing about the impeller with an inlet formed through the housing in axial alignment with the center of rotation of the impeller,

blade elements mounted on the impeller and arranged to rotate about the housing inlet, forming a central cavity at the center of rotation,

and a circular valve element captured within the cavity by the blade elements as guides, a first rim arranged to engage the impeller when fluids flo w through the inlet and push the element to the impeller, and a second rim arranged to engage the housing about the inlet as a seat when the impeller is stopped and fluid flows from the housing exit to push the element to the inlet.

5. The pump mechanism of claim 4 in which, the central portion of the valve element is formed as inverted cone which acts as a distributor of the fluids from the inlet to the blade elements.

6. The pump mechanism of claim 5 in which, the impeller is provided with a hole through which the pressure across the element is kept equalized to obviate the element being retained against the impeller when stopped.

References Cited UNITED STATES PATENTS 1,382,665 6/1921 Myers 103113 2,542,896 2/1951 Brady 103-87 3,128,822 4/1964 Tyler 10397 3,142,259 7/1964 Tyler 10397 ROBERT M. WALKER, Primary Examiner.

U.S. C1.X.R. 

